When a patient is required to stay in a hospital bed at a hospital or other patient care facility, it is desirable for a caregiver to be able to monitor the presence, absence, and movement of the patient on the bed platform, generally a mattress, and to monitor the patient's activity level. Caregivers are generally responsible for a number of patient-related activities, examples of which include monitoring the presence or absence of patients on their hospital beds and/or monitoring patient movement relative to their hospital beds.
One system for monitoring patient movement on a hospital bed is disclosed by U.S. Pat. No. 5,276,432, issued Jan. 4, 1994, to Travis. The disclosed system calculates the center of gravity of a patient within a two-dimensional Cartesian coordinate-based region defined relative to the patient-supporting surface of the bed mattress. The center of gravity of the patient relative to the region is determined using data from load cells coupled to the hospital bed frame. Patient movement relative to the region is detected by monitoring movement of the center of gravity of the patient, and by determining the location of the patient's center of gravity relative to the region.
Alternative methods and systems for monitoring patient movement on, exit from and/or impending exit from, a hospital bed are desirable.